I have not yet been able to install these in my 2017 Honda Ridgeline as Honda has done an extremely tidy job with cabling and use of space. I had asked customer service if everything was included as the single horn I originally had ordered, which would have been a much easier installation, suddenly was on indeterminate backorder, and required purchasing a separate wiring harness and relay. Although CS said yes, a non-waterproof relay is all the addition included with the sparse instructions.
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